<!DOCTYPE html>
<html lang="en">

<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
</head>

<body>
    <!-- 
        验证断点中的作用域链为
        Local: {
            this: undefined,
            a11: 'a11',
        }
        Script: {
            a1: 'a1',
        }
        Global: {
            a: 'a',
            ...
        }
        并且中断时作用域的内容是可更改的
     -->
    <script>
        var a = 'a';
    </script>
    <script>
        let a1 = 'a1';
        (() => {
            let a11 = 'a11';
            debugger;
            console.log(a, a1, a11);
        })();
    </script>
</body>

</html>